WiFi chips tend to draw alot of current while in use. This high current drain often makes it infeasible to run certain kinds of WiFi applications on cellular devices. Even though certain power saving features have been proposed, they do not appear to be efficient enough to run certain WiFi applications on a cellular device even when the device is in passive mode without significantly impacting the standby time. A few examples of such applications include: peer discovery, routing information exchanges, and traffic monitoring.
While synchronizing to a reliable external timing source such as a GPS signal can facilitate timing synchronization between WiFi devices, all WiFi devices may not be able to receive the external timing signal because of their location and/or because they do not include a receiver capable of receiving such a signal. Accordingly, in WiFi systems it is important that beacon signaling which is used in the WiFi protocol continue to be used between devices to maintain device synchronization even if one or more devices are capable of receiving signals from an external non-WiFi timing signal source.
Individual devices in WiFi rely on their internal timing clocks to maintain ongoing timing synchronization to determine the passage of time from a point in time where a synchronization operation occurs, e.g., from a point in time where a timing adjustment is made based on the receipt of a beacon signal.
It would be desirable if a device with a high degree of timing reliability, e.g., because of its ability to maintain and update its timing based on a reliable external timing signal such as a GPS signal could operate as a master device in a WiFi network and control the timing of the devices in the WiFi network. However, it should be appreciated that a large amount of signaling overhead with regard to establishing a master/client relationship with regard to timing synchronization should be avoided if at all possible to allow as much of the communication capacity to be used for other functions, e.g., the communication of traffic data.
In view of the above discussion, it should be appreciated that there is a need for new and/or improved methods relating to timing synchronization between devices in a communications network such as a WiFi network. It would be desirable if a device with reliable timing synchronization could act as a master timing control device but with little or no overhead relating to the device explicitly signaling that it is acting as a master timing control device in the network.